The present invention relates to an apparatus for protecting marine risers extending underwater from offshore oil drilling rigs in icy waters against damage due to the pressure of ice floes.
Offshore platforms such as oil drilling rigs on the open sea have marine risers extending underwater from the platform toward the sea bottom. The conventional drilling platforms have been equipped with no apparatus for protecting the marine risers from ice floes.
The marine risers therefore have suffered from the problem of being broken or otherwise damaged by ice floes which hit or are pressed against the marine risers. One known way to solve this problem has been to use specially designed marine risers rugged enough to withstand the hitting or pressing engagement with ice floes during the season in which floating ice is expected to come around the offshore platforms. The offshore structure used in icy waters are therefore costly to construct.